Advances in Human Internal Radiation Counting at Los Alamos: Multiple Simultaneous in-Vivo Measurements

摘要

In order to improve the health physics surveillance program for radiation workers at the Los Alamos Scientific Laboratory (LASL), the In-Vivo Measurements Laboratory at LASL is being ungraded to provide four separate, yet simultaneous, photon spectral measurements on a single individual, with each spectrum providing different information. The four spectra are acquired with the following four detectors and respective energy regions: the NaI portion of twin phoswich detectors placed over the chest of the subject and monitoring the 10 to 140 keV photon region (for Pu isotopes and exp 241 Am), the CsI portion of the same phoswich detectors and monitoring the energy region from 200 to 2000 keV (for background radiation, exp 137 Cs, etc.), a large planar hyperpure germanium detector placed directly over the liver area of the prone subject and monitoring the region 10 to 250 keV (for gamma activity in special organs), and a large volume Ge(Li) detector placed directly under the prone subject and monitoring the region 55 to 2000 keV (for exp 137 Cs, etc.). Data analysis is performed on-line by a minicomputer, with printer output and permanent data storage on floppy diskettes. The simultaneous counts allow potential health physics problems to be identified earlier and provide a more comprehensive monitoring program at no increase in operating costs and a modest increase in capital costs. (ERA citation 03:041693)